West Pacific/2015/11W/Archive/20
Public advisory TYPHOON NANGKA PUBLIC ADVISORY NUMBER 20 WIKI-HURRICANES FORECASTING CENTER 12:00 PM JST WED JUL 08 2015 ...CATEGORY 3 NANGKA CONTINUING WEST-NORTHWEST... SUMMARY OF 12:00 PM JST...03:00 UTC...INFORMATION ------------------------------------------------------------------- LOCATION...15.5N 150.1E CENTER POSITION CONFIDENCE: HIGH ABOUT 295 MI...475 KM ENE OF SAIPAN, MARIANA ISLANDS MAXIMUM SUSTAINED WINDS...110 KT...125 MPH...205 KM/H MINIMUM BAROMETRIC PRESSURE...942 MB...27.82 INCHES PRESENT MOVEMENT...WNW AT 10 KT...12 MPH...19 KM/H DISCUSSION AND 48-HOUR OUTLOOK --------------------------------------------- At 12:00 pm JST, the center of Typhoon Nangka was situated near 15.5N 150.1E, or about 295 miles (495 km) east-northeast of Saipan, Mariana Islands. Maximum sustained winds were 110 knots (125 mph, 205 km/h), with higher gusts. The minimum barometric pressure was 942 millibars (hPa; 27.82 inHg), and the cyclone was tracking west-northwest at 10 knots (12 mph, 19 km/h). Fluctuations in intensity are likely over the next 48 hours as Nangka approaches the Mariana Islands. NEXT ADVISORY ------------------- Next complete advisory at 6:00 pm JST. $$ Forecaster TAWX14 Discussion TYPHOON NANGKA DISCUSSION NUMBER 20 WIKI-HURRICANES FORECASTING CENTER 12:00 PM JST WED JUL 08 2015 Typhoon Nangka has changed little in organization over the past six hours. The eye, which became completely obscured in infrared imagery this morning, has warmed a bit. However, convection within the eyewall has continued to warm, with -70°C convection confined to the southwestern quadrant. Recent satellite intensity estimates were T5.0/90kt from JTWC, T5.5/102kt from SAB, and T5.6/104.6kt from UW-CIMSS ADT. While this would typically support an intensity of approximately 100kt, the initial intensity has been held at 110kt for now in light of a fairly steady state presentation. Nangka's current weakening seems to be the result of a moderate 10 to 20 knots of wind shear from an upper-level trough to the cyclone's north-northwest. Over the coming days, this trough is expected to drift west-northwestward in tandem with the storm while steadily weakening. As a result, little change in intensity is forecast over the next 24 hours, succeeded by some intensification between 24 and 48 hours. After day 2, increased wind shear is expected as an upper-level trough dives southeastward, and Nangka is forecast to maintain intensity once again. By the very end of the forecast period, there are indications that the upper-level environment will once again become favorable. Nangka continues on its steady west-northwest track this afternoon, steered by a mid-level ridge across the northern West Pacific. The approach of the upper-level trough in approximately 48 hours is expected to erode the western extent of this anticyclone and force the typhoon on a more poleward track. The updated track forecast is largely unchanged from the previous one. Nangka is expected to approach the northern Mariana Islands in about 36 hours, and residents there should be preparing for potentially life-threatening conditions. INIT 08/0300Z 15.5N 150.1E 110 KT 125 MPH 12H 08/1200Z 16.3N 148.4E 110 KT 125 MPH 24H 09/0000Z 17.2N 146.4E 110 KT 125 MPH 36H 09/1200Z 17.9N 144.9E 115 KT 130 MPH...NEAR NORTHERN MARIANA ISLANDS 48H 10/0000Z 18.6N 143.3E 120 KT 140 MPH 72H 12/0000Z 19.8N 141.2E 115 KT 130 MPH 96H 12/0000Z 20.4N 141.0E 110 KT 125 MPH 120H 13/0000Z 22.5N 140.7E 115 KT 130 MPH $$ Forecaster TAWX14